San Diego, CA USA (UroToday.com) In the coming decades, the prevalence of nephrolithiasis is expected to increase dramatically, due to risk factors such as climate, obesity, and age. With the prevalence of nephrolithiasis in the US currently at an estimated 8.8%, determining the impact these risk factors will have on stone burden rates in the coming years is essential.

In this study, Dr. Cui and colleagues developed a predictive model for nephrolithiasis burden, evaluating the impact climate, demographics, and obesity will have on stone formation for the next 35 years.

The authors performed extensive review of the nephrolithiasis literature, identifying all studies reporting quantifiable risk ratios for large database analyses. The selected risk factors were race, age, sex, obesity, and mean annual regional temperature. All were included in a continuous model, accommodating for complex, nonlinear relationships between variables.

From this model, the authors expected the nephrolithiasis burden to increase to 10.6% in the next 35 years. Although increasing obesity was the driving factor behind this rise in stone burden, increases in age across the white demographic and in size of the Hispanic working class acted as balancing factors. Nevertheless, this 1.8% rate increase, when coupled with expected population growth, corresponds with almost double the current stone burden population and healthcare costs of over $4 billion.